This article describes how unregistered practitioners, such as healthcare assistants and community-based mental health workers, can contribute to the learning, support and development of pre-registration nursing students in clinical practice. It presents the results of an unregistered practitioner co-mentoring scheme piloted in a mental health trust, and demonstrates its benefits for nursing students, unregistered practitioners and nurse mentors. The scheme delivers training and supervision for unregistered practitioners who are starting a formal role in clinical learning. It aims to recognise and develop the contribution of unregistered practitioners to student learning, and to enhance the learning environments in which nursing students train.